Been there, done that
Bill,
Here's a bit I posted 2 months ago to a guy who needed access to his fuel lines. The tank is below the port side locker at the helm seat. The tank is below the floor. Remove your batteries and there is an access panel in the floor. Unfortunately, it's not really over the fittings. I'll bet you didn't know you had a fuel gauge there either, did you?
Previously posted:
2 seasons ago I had to replace the entire fuel tank on my '92 H33.5. My advice is to leave the aft cabin bulkhead intact. For one, the fuel tank is about 1/2" away on the other side. Even though it is aluminum you risk damaging it with a hole saw. Secondly, I liked the idea of a solid (though thin) bulkhead between my fuel tank and my sleeping qtrs.
I went through the locker floor. I was looking for an excuse to buy a sawzall anyway. You may be able to use the holesaw to gain access to the fittings but I had to cut the entire floor out to remove and replace the tank. I unscrewed it along the forward and aft bulkheads and cut fore and aft about 1"-2" inside of the electric panel and also cut fore and aft as close to the boats centerline as the walk through would allow.
When it came time to re-construct I removed the support cleats along the forward and aft bulkheads where I had cut the floor away and remounted them higher to be even with what was left of the floor by the electric panel and under the walkthrough. I used the old floor as a pattern for the new floor and just added 2" on each end to sit on the old floor and the repositioned cleats. Coated the new 3/4" plywood floor with epoxy, painted it and screwed it in place. Oh, I also made an access panel in the new floor so I can get to the fittings anytime I want, at least anytime I want to remove the batteries.